1. Field of the Description
The present description relates, in general, to three dimensional (3D) display methods and devices (e.g., methods and devices for creating and augmenting differing views of objects and their background in differing directions without regard of eye position and without need for head-mounted gear to view a 3D effect), and, more particularly, to 3D or volumetric displays that combine multiple emissive and light modulating planes that are adapted to provide views of objects with opacity against other objects or background that can be controlled on a pixel-by-pixel basis (e.g., provide controllable per-pixel opacity).
2. Relevant Background
Displays that provide the illusion of three dimensions (3D) have become increasingly popular in many entertainment settings from movie theaters to venues such as amusement parks, shopping malls, and the like to home viewing with advances in televisions, computer monitors, video game systems, transparent displays, and interactive windows. The trend toward 3D display devices is likely to continue and is being driven in part by the increasing amount of 3D content available for movies, television, and video games.
While the majority of 3D displays currently require that the audience or viewers wear special glasses, there has recently been significant research toward autostereoscopic and automultiscopic displays. In automultiscopic display systems, techniques are used to display 3D images that can be viewed without the use of special headgear or glasses. It is generally agreed within the entertainment industry that automultiscopic displays unencumbered by glasses offer significant advantages over other 3D displays. Technological progress has been made in providing automultiscopic displays with improved resolution and user-perceived quality, and such progress may soon lead to more widespread adoption of automultiscopic displays as long as issues with occlusion and limitations on user viewing positions can also be addressed.
A volumetric display is one of the main types of 3D display that is currently used to provide an automultiscopic experience. Volumetric displays provide images of 3D objects with correct focus and depth cues by creating a volume of individually controlled light sources. Volumetric displays typically operate by superimposing translucent light emitters, and, as a result, a key disadvantage with volumetric displays is that they cannot represent occlusion or view-dependent effects (e.g., a viewer can often see objects behind a displayed foreground image instead of the foreground image occluding or blocking the object from view). In conventional volumetric displays, all voxels that are occluded by other voxels in an input 3D model are visually merged since there are no mechanisms to block the light and provide proper occlusion.
A variety of display systems and devices have been developed to try to provide improved 3D displays that include and augment the physical background environment while not requiring viewers to wear special glasses or headgear. For example, displays have been developed that in some cases can control each pixel's color, luminance, and opacity, and these displays include Pepper's Ghost display systems, scrim projection-based systems, and transparent organic light-emitting diode (OLED) displays with transparent liquid-crystal display (LCD) masks. While effective, the masked Pepper's Ghost display system requires a large beam combiner creating a large footprint. The masked scrim projection-based system has a small physical footprint, but it needs space for projection throw. Transparent OLED displays with co-located LCD masks have a minimal footprint and allow for direct interaction with the display surface. Unfortunately, current commercial transparent OLED displays are limited in size (2″×2″), and larger research displays (e.g., displays that are greater than 15 inches diagonal) are unavailable outside the laboratory.
Additionally, a switching dual layer display system has been developed in which a foreground display was used to present opaque emissive content on a transparent field, independent of the content on the background display. In this display system, the components are rapidly switched between two states: (1) a foreground transparent LCD panel presenting its content with a background display presenting a white field acting as a global backlight; and (2) the foreground display presenting a content mask with the background display presenting its content. The foreground display's pixels exhibit controllable color, luminance, and opacity, but one drawback of such a system is that it requires and depends upon the background display.
Hence, there remains a need for improved 3D displays (or display systems) and automultiscopy display methods that can better handle occlusions and other issues limiting use of such displays such as limited number of viewers/viewpoints, specific and tight viewer positioning requirements, and aliasing artifacts. Preferably, such 3D display systems would be configured to try to replicate the abilities and compactness of 3D systems with a transparent OLED display and LCD mask.